Radiator mechanism and electronic apparatus

ABSTRACT

It is an exemplified object of the present invention to provide a radiator mechanism and electronic apparatus having the radiator mechanism that can prevent destruction, deterioration, and malfunction due to heat of exoergic components or other electronic components, thermal deformation of a housing thereof, and low-temperature burn, without preventing the electronic apparatus including a printed board from miniaturization. The radiator mechanism is comprised of a cooling fan and a through hole provided in a motherboard, thereby thermally protecting a variety of circuit components mounted on the motherboard to provide a stable operation.

BACKGROUND OF THE INVENTION

The present invention relates generally to radiator mechanisms, and moreparticularly to a radiator mechanism that includes a cooling fan fordissipating heat derived from exoergic circuit components (orheat-producing components) mounted in an electronic apparatus. Thepresent invention is suitable, for example, for a mounting method of thecooling fan for various types of circuit components mounted on amotherboard in a notebook personal computer (PC) or the like.

The motherboard (or main board) in the notebook PC is mounted with thecircuit components such as a CPU socket, a variety of memory (sockets),a chipset, an expansion slot, and a BIOS ROM, and directly affectsperformance and functionality of the PC.

The notebook PCs in recent years tend to include increased number ofexoergic components and to generate more calorific values from thevarious circuit components, as the circuit components mounted on themotherboard provide higher speed and higher performance. Therefore, inorder to thermally protect the exoergic components and other circuitcomponents mounted directly or via a socket or the like on themotherboard, the motherboard is provided with a cooler called heat sink.

The heat sink typically includes a cooling (or radiating) fin made up ofmany high-thermal-conductivity members, and cools exoergic components byspontaneous air cooling. However, the calorific values from exoergiccomponents tend to become too high in recent years to be adjusted by thespontaneous air cooling. Therefore, a fan-cum-heat sink furtherincluding a cooling fan has been proposed to enhance a cooling effect ofthe heat sink. The fan-cum-heat sink provides forced-air cooling to theheat sink utilizing air currents produced by a fan. A conventionalfan-cum-heat sink is typically provided above a CPU on the motherboard,as the calorific value from the CPU is the highest among othercomponents.

The cooling fan may be classified into two types: a lateral type thatorients perpendicular to one surface of the motherboard; and alongitudinal type that orients parallel with the surface of themotherboard. However, the lateral type is more suitable than thelongitudinal type that requires substantial space allocation to acertain thickness for recent notebook PCs required to have a thin (orlow-profile) body.

However, the exoergic components are mounted also on a reverse surfaceof the motherboard opposite to a surface on which the heat sink ismounted. In a conventional embodiment, the calorific values derived fromthese components are almost negligible, but increased speed and enhancedfunctionality in recent years have made these calorific valuesnonnegligible, and influences such as destruction, deterioration, andmalfunction due to heat of the exoergic components and other circuitcomponents, thermal deformation of the housing accommodating themotherboard, low temperature burn, and the like have been increasingaccordingly. Therefore, the necessity has been arising for themotherboard to be cooled at the both sides (front and back surfaces) inrecent years.

To remove the necessity, it would be a conceivable plan to providecooling fans at the both sides, but this plan would entail increasedmanufacturing costs, increased power consumption for driving the coolingfans, and increased noise caused by driving the cooling fans.

In this respect, a radiator mechanism that cools both sides of amotherboard using one cooling fan is proposed as disclosed in JapaneseLaid-Open Utility Model Application, Publication No. 6-13364. Theradiator mechanism 10, as shown in FIG. 7, includes an outer frame 1, acooling fan 2, fixing tonguelet pieces 3, a connector 4, a motherboard5, and a connector 6. FIG. 7 is a schematic perspective view of theconventional radiator mechanism 10. The outer frame 1 is fixed in athrough hole provided in the motherboard 5 via the fixing pieces 3 andscrews (not shown) provided at both sides of the outer frame 1. As aresult, the connectors 4 and 6 are electrically connected with eachother, and the cooling fan 2 is electrically connected with themotherboard 5.

The cooling fan 2 shown in FIG. 7 has the outer frame 1 embedded in themotherboard 5, and thus may cool the both sides of the motherboard 5 atthe same time. In addition, a shift of a mounting position of the fixingpieces 3 provided on the outer frame 1 in an up or down direction to anarbitrary spot would vary a mounting height of the outer frame 1relative to the motherboard 5, so that a surface generating morecalorific value may be effectively cooled.

However, the cooling fan 2 is the longitudinal type, and thus is notsuitable for a low-profile notebook PC as described above. Accordingly,a radiator mechanism that can efficiently cool the both sides of themotherboard without preventing the notebook PC from achieving a slimbody has been in increasing demand.

BRIEF SUMMARY OF THE INVENTION

Therefore, it is an exemplified general object of the present inventionto provide a novel and useful radiator mechanism and electronicapparatus having the radiator mechanism in which the above disadvantagesare eliminated.

Another exemplified and more specific object of the present invention isto provide a radiator mechanism and electronic apparatus having theradiator mechanism that can prevent exoergic components and otherelectronic components from suffering destruction, deterioration, andmalfunction due to heat, a housing accommodating these components fromsuffering thermal deformation and low-temperature burn, and theelectronic apparatus including a printed board from achieving a slimbody.

In order to achieve the above objects, a radiator mechanism as oneexemplified embodiment of the present invention comprises a board onwhich an exoergic part is to be mounted, the board including a throughhole, and a cooling fan that orients perpendicular to one surface of theboard. The cooling fan can dissipate heat from the one surface, and thethrough hole allows the cooling fan to dissipate through the throughhole heat from a back surface of the one surface. Since this radiatormechanism includes a lateral type cooling fan, a housing of anelectronic apparatus that accommodates the printed board is notprevented from miniaturizing so much as in case a longitudinal typecooling fan is used. The cooling fan does not employ the through holefor dissipating heat at a surface on which the cooling fan is provided.The through hole has dimensions enough to allow the cooling fan to coolthe back surface. As a result, heat at the back surface may easily bedissipated as well with a single cooling fan. The cooling fan istypically provided on the board, but may be provided at a side of thehousing that accommodates the board.

The above radiator mechanism may further comprise a heat sink, and theabove cooling fan may be provided in the heat sink. In this case, thefan-cum-heat sink may have an enhanced cooling capability, and isprovided with the cooling fins and cooling fan in the same plane, whichcontributes to a slimmed body of the radiator mechanism. The aboveexoergic part is, for instance, a processor, the above board is, forinstance, a motherboard, and the above cooling fan is, for instance, isprovided at a side of the same surface of the motherboard on which theprocessor is provided. The processor conceptually includes a CPU. Inthis case, the radiator mechanism may utilize the cooling fan for CPU inthe fan-cum-heat sink, which is conventionally provided, without anadditional cooling fan, for the inventive radiator mechanism, so thatthe cooling fan may have expanded functionality.

The above radiator mechanism may further comprise a heat pipe, and theabove cooling fan may be configured to dissipate heat conducted via theheat pipe. The above heat pipe and the above heat sink may be thermallyconnected. The heat pipe may be disposed between the one surface and theback surface of the one surface, via the through hole. In this case, theradiator mechanism allows the heat pipe, if joined with a specificheat-producing source (exoergic member), to cool the specific portionefficiently and intensively.

The above cooling fan may include an intake connected to the thoroughhole. In this case, the cooling fan may dissipate heat at the backsurface via the intake and the through hole. The intake may be piercedthorough the housing that accommodates the cooling fan.

An electronic apparatus as one exemplified embodiment of the presentinvention comprises a board that includes first and second surfaces, anda through hole pierced through the first and second surfaces; exoergicparts mounted on the first and second surfaces of the board; a coolingfan that orients perpendicular to the first surface and dissipates heatfrom the first surface, while dissipating heat from the second surfacevia the through hole; and a housing that accommodates the board and thecooling fan. This electronic apparatus has the above-described radiatormechanism, and thus may efficiently cool the both sides of the boardwhile keeping a slimmed body of the housing. This electronic apparatusis suitably applicable to notebook PCs, word processors, personaldigital assistants (PDAs), and other portable electronic apparatuses(such as portable game machines, and varied types of drives).

The above electronic apparatus may further comprise a heat sink havingmany fins, the above cooling fan and the cooling fins may constitute afan-cum-heat sink, and the cooling fan and the cooling fins may bedisposed in the same plane. In this case, the fan-cum-heat sink may havean enhanced cooling capability, and is provided with the cooling finsand cooling fan in the same plane, which contributes to a slimmed bodyof the fan-cum-heat sink itself. One of the above exoergic part is, forinstance, a processor, the above board is, for instance, a motherboard,and the above cooling fan is, for instance, is provided at a side of thesame surface of the motherboard on which the processor is provided. Theprocessor conceptually includes a CPU. In this case, if the aboveelectronic apparatus is embodied as a notebook PC, ahigh-heat-dissipation-performance low-profile notebook PC may beprovided. Further, the electronic apparatus may utilize the cooling fanfor CPU in the fan-cum-heat sink, which is conventionally provided in anormal notebook PC, without an additional cooling fan, for the inventiveelectronic apparatus, so that the cooling fan may have expandedfunctionality.

The above electronic apparatus may further comprise a heat pipe, and theabove cooling fan may be configured to conduct heat via the heat pipe.In this case, the electronic apparatus allows the heat pipe, if joinedwith a specific heat-producing source (exoergic member), to cool thespecific portion efficiently and intensively.

The above cooling fan may include an intake connected to the throughhole. In this case, the cooling fan may dissipate heat at the backsurface via the intake and the through hole. The above intake may bepierced through a housing that accommodates the cooling fan.

Other objects and further features of the present invention will becomereadily apparent from the following description of the embodiments withreference to accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a radiator mechanism as oneexemplified embodiment of the present invention.

FIG. 2 is a perspective view of a motherboard in the radiator mechanismshown in FIG. 1 as viewed from a back thereof.

FIG. 3 is a magnified perspective overview of a fan-cum-heat sink in theradiator mechanism shown in FIG. 1.

FIG. 4 is a perspective view for illustrating an inside of thefan-cum-heat sink shown in FIG. 3.

FIG. 5 is a schematic perspective view of a notebook personal computerto which the radiator mechanism shown in FIG. 1 is applicable.

FIG. 6 is a schematic perspective view of the fan-cum-heat sink asanother exemplified embodiment of the present invention.

FIG. 7 is a magnified perspective overview of a conventional radiatormechanism.

DETAILED DESCRIPTION OF INVENTION

Referring now to FIGS. 1 to 4 inclusive, a description will be given ofa radiator mechanism 100 as an exemplified embodiment of the presentinvention. The inventive radiator mechanism includes at least a lateraltype-cooling fan, but the present embodiment employs a cooling fan 130in a fan-cum-heat sink 110. The radiator mechanism 100 in the presentembodiment is comprised of the fan-cum-heat sink 110, and a motherboard160 provided with a through hole 166. FIG. 1 is an exploded perspectiveview of the radiator mechanism 100 as an exemplified embodiment of thepresent invention. FIG. 2 is a perspective view for illustrating a backsurface of the motherboard 160 in the radiator mechanism 100. FIG. 3 isa magnified perspective overview for showing the fan-cum-heat sink 110shown in FIG. 1. FIG. 4 is a perspective view for illustrating an insideof the fan-cum-heat sink shown in FIG. 3.

The radiator mechanism 100 in the present embodiment utilizes thefan-cum-heat sink 110 provided on the CPU 150 (or MPU: both termsindicate a processor in a broad sense; hereinafter used in a likemanner) represented by a dotted line in FIG. 1 in such a manner as toget in thermal contact with the CPU 150 to cool the CPU 150. Thefan-cum-heat sink 110 includes a housing 120, a cooling fan 130, and acooling fin having a plurality of fins 142 (see FIG. 4).

The housing 120 is an approximately rectangular parallelepiped framecomposed, for instance, of aluminum, copper, aluminum nitride,artificial diamond, plastic, or other high-thermal-conductivitymaterials, and includes a top surface 122, mounting grooves 123 a,mounting holes 123 b, a bottom surface 124, an intake 125, an endsurface 126, an exhaust port 127, and a storage portion 128. The heatsink 110 is manufactured by sheet metal working, aluminum die casting,or other processes. The housing 120, if made of plastic, may be formed,for example, by injection molding. Apart of the housing 120 (e.g., acooling fan 130 and a cooling fin 140) may be configured to beseparable.

The intake 125 is, to be specific, provided as holes on both sides at atop surface 122 and a bottom surface 124 of the housing 120. As shown inFIG. 3, the intake 125 is pierced through the top surface 122 and thebottom surface 124. To make the matter more intelligible, referring toFIG. 4, the bottom surface 124 proves to be also provided with theintake 125. The fan-cum-heat sink 110 (as shown in FIGS. 1 and 3) cantake in air from the both sides of the top and bottom surfaces 122 and124 of the heat sink 110.

For convenience of replacement and maintenance of the cooling fan 130and/or the cooling fin 140, the top surface 122 of the housing 120 ispreferably configured to be like a lid removable from a main bodyincluding the bottom surface 124. Alternatively, a lidless heat sink asshown in FIG. 4 may be used instead of the heat sink shown in FIG. 1,but it is preferable to provide such a lid portion to reduce noisegenerated by rotation of the cooling fan 130.

The housing 120 accommodates the cooling fan 130 and the cooling fin 140in the storage portion 128. The storage portion 128 includes asemicircular portion for storing the cooling fan 130, and a rectangularparallelepiped portion for storing the cooling fin 140. The storageportion 128 also serves as a wind tunnel to provide space through whichairflow generated by the cooling fan 130 passes. The housing 120 mayalso dissipate heat from a surface thereof, and thus if necessary maymake the top and bottom surfaces 122 and 124, and other surfacesprotuberantly shaped so as to increase surface areas, thereby enhancingdissipation effects.

As in FIG. 1, the mounting grooves 123 a and mounting holes 123 b arepierced through the top and bottom surfaces 122 and 124, and are engagedwith screws 170. The screws 170 may have a hollow body so as to beengageable with pins 172 pierced through a socket 151 for placement ofthe CPU 150 provided on the motherboard 160. The socket 151 makes theCPU 150 exchangeable. Alternatively, the screws 170 are pierced throughthe holes (not shown) on the motherboard 160 and fastened on themotherboard 160, if needed, via nuts (not shown), or the like. As aresult, the housing 120 is secured on the motherboard 160 through themounting grooves 123 a and the mounting holes 123 b, and the screws 170.However, any means for thermally connecting the housing 120 and the CPU150 is applicable. For instance, the both elements may be bonded with athermally conductive adhesive or by soldering (with solder paste and areflow oven, or otherwise), or fastened by coil springs each looped overa portion projected from the mounting grooves 123 a and the mountingholes 123 b upon insertion of mounting pins each having a slit head froma surface 164 that will be described later on the motherboard 160.

As shown in FIGS. 1, 3, and 4, the intake 125 is pierced through the topand bottom surfaces 122 and 124 to connect the cooling fan 130 to theoutside. The intake 125 is also connected to the through hole 166 thatwill be described later in the motherboard 160. An end surface 126includes the exhaust port 127, which is connected to the cooling fan 130and the cooling fin 140. The intake 125 serves to introduce hot airderived from exoergic components mounted broadly on the motherboard 160as well as from heat generated in the CPU 150 into the housing 120.

As a result, the intake 125 can introduce, on the top and bottomsurfaces 122 and 124, hot air located at a side of the surface 162 thatwill be described later of the motherboard 160 into the housing 120, andcan introduce, on the bottom surface 124, hot air located at a side ofthe surface 164 that will be described later of the motherboard 160 viathe through hole 166 into the housing 120. In other words, the hot aircan be introduced into the housing 120 from the both sides (the surfaces122 and 124) of the cooling fan 130. The introduced hot air is suppliedto the cooling fin that will be described later by the cooling fan 130,and after heat exchange, ejected through the exhaust port 127. Theintroduced hot air is cooled by the heat exchange. The exhaust port 127is connected to sheet metal for heat radiation (not shown) incorporatedin a side portion 225 of the notebook PC 200 that will be describedlater or to a vicinity of the exhaust port 127 provided on the sideportion 225. As described above, heat in the air is also dissipated froma surface of the housing 120.

The intake 125 is so large as to expose the cooling fan 130 in whole inthe present embodiment, but the size may be set arbitrarily. The intake125 may be comprised of a plurality of holes (e.g., assuming a meshstructure), if necessary.

If required, the housing 120 may include a hollow bottom portion havingthe bottom surface 124, in which cooling water or other refrigerants(e.g., Freon, alcohol, ammonia, galden, and fron) are contained to forma heat pipe plate. In addition, inserting a mesh (or wick) in the hollowportion, which induces a capillary phenomenon, thereby circulatingcooling water, would be further effective. Moreover, the housing 120, ifnecessary, may be connected with an external heat pipe, or the like.This heat pipe may include a pipe that is made of aluminum, stainlesssteel, copper, or the like, and formed so as to have portions varied inheight. The pipe has a wick material made of glass fiber, reticular thincopper wire, or the like affixed inside, and under reduced pressure,stores cooling water or other refrigerants. The cooling water coolsexoergic elements by repeating the following cycle: having obtained heatfrom the exoergic elements in a lower position, the cooling water isvaporized and moves up to a higher position, and then is spontaneouslyor forcefully cooled in the higher position, liquefied, and returns tothe lower position. If the above heat pipe is coupled with a specificheat source, efficient and concentrated cooling can be provided for thatportion.

As another embodiment, a heat pipe 61 connected with a fan-cum-heat sink110 may be extended to a back surface 164 of the motherboard 160 usingthe through hole 166. This embodiment is shown in FIG. 6. To a sidesurface of the fan-cum-heat sink 1100 shown in FIG. 6 is coupled theheat pipe 61. The heat pipe 61 extends from the front surface 162 of themotherboard 160 via the through hole 166 to the back surface 164 of themotherboard 160. In a dotted portion of the heat pipe 61 in FIG. 6, aportion under the intake 125 passes through the through hole 166 of themotherboard 160. The motherboard 160 is not illustrated in FIG. 6. Theheat pipe 61 is coupled with exoergic elements such as electroniccomponents in a position indicated by 62 in the drawing at the backsurface 164, and transfers heat derived therefrom to the fan-cum-heatsink 1100. Accordingly, the heat conducted via the heat pipe 61 isdissipated using the cooling fan 130. This configuration allows thethrough hole 166 to double as an intake from the back surface 164 and aplacement of the heat pipe. A structure of the fan-cum-heat sink 1100 inFIG. 6 is the same as the fan-cum-heat sink 110 in FIGS. 1, 3, and 4except coupling of the heat pipe 61. Therefore, an illustration of thecooling fan 130 and the like is omitted.

The cooling fan 130 rotates, produces airflow, and thereby forcefullycools the cooling fin 140. The cooling fan 130 includes a motor portion132, a propeller portion 134 fastened to the motor portion 132. Themotor portion 132 typically includes an axis of rotation, a bearingprovided around the axis of rotation, a bearing house, and a magnetmaking up a motor, but since any structure known in the art may beapplied to the motor portion 132, a detailed description will beomitted. However, in order to prevent heat transfer to the bearinghouse, a thermal insulation portion is preferably formed on an innerwall surface of the bearing house. The thermal insulating portion is,for example, formed of a low-thermal-conductivity material such as afluoroplastic, a silicon resin, or the like into a thin film.

The propeller portion 134 includes a desired number of rotor blades eachforming a desired angle. The rotor blades may orient so as to form equalor unequal angles, and have a desired dimension. The motor portion 132and propeller portion 134 in the cooling fan 130 may be separable orunseparable. An illustration of wiring connected with the cooling fan130 is omitted. As described above, the intake 125 is provided at bothsides (surfaces 122 and 124) of the housing 120, and thus the coolingfan 130 may take in air from the both sides.

The cooling fan 130 in the present embodiment orients perpendicular toone surface (the front surface 162), and thus is considered to be alateral type. This may therefore allow the notebook PC 200 in which thecooling fan 130 is included to maintain a low-profile body of the base220. Moreover, the cooling fan 130 is placed in the same plane as thecooling fin 140 that will be described below, and this configurationalso contributes to a slimmed body of the base 220 in the notebook PC200 that will be described later. As described above, the through hole166 of the motherboard 160 is located under the cooling fan 130.

The cooling fin 140 is comprised of neatly aligned many plate-shapedfins 142. The cooling fin 140 includes a convex portion to increase asurface area thereof, thereby enhancing dissipation effects. However,the shape of the fins 142 is not limited to one like a plate, and anyplacement shapes like a pin, a curve, etc. may be adopted. The fins 142do not necessarily have to be aligned horizontally with equal spacing,but may be placed so as to be radial, or oblique relative to the bottomsurface 124. Moreover, the fins 142 may be placed around the cooling fan130. The number of the fins 142 may be set arbitrarily. The fins 142 arepreferably made of a high-thermal-conductivity material such asaluminum, copper, aluminum nitride, artificial diamond, and plastic. Thefins 142 are formed by molding, a press fit, brazing, welding, injectionmolding, or the like.

In the storage portion 128, the CPU 150 is located immediately below aposition in which the cooling fin 140 is placed. In other words, in aportion surrounded with the mounting holes 123 a and the mountinggrooves 123 b in the storage portion 128, the cooling fin 140 is formed.The cooling fin 140 and the CPU 150 are thermally connected, andconsequently heat from the CPU 150 is efficiently transferred to thecooling fin 140. Moreover, the cooling fin 140, which receives airblowing from the cooling fan 130, may efficiently dissipate heat.

The fan-cum-heat sink 110 in the present embodiment is, in general,higher in radiative efficiency than a heat sink configured to have thecooling fan 130 placed above the cooling fin 140. This is: (1) becausethe cooling fan above the cooling fin blocks air from the propellerportion, reducing the amount of air to the cooling fin immediately belowthe motor portion, and inhibits effective cooling performance; (2)because heat producing sources in a CPU concentrate in a central portionthereof; and for other reasons. However, the cooling fin 140 in thepresent embodiment exhibits high radiative efficiency because noimpediment is placed against convection by the motor portion 132.

Optionally, a thermally conductive elastic body (e.g., silicon rubber)may be inserted between the cooling fin 140 and the top surface 122 sothat heat conducts therebetween to enhance a radiative efficiency. Thisstructure also serves to eliminate a vibration in the cooling fin 140caused by a rotation of the cooling fan 130 and a noise accompanied bythe vibration. The thermally conductive elastic body's absorption of thevibration accompanied by the rotation of the cooling fan 130 wouldeventually prevent screws 170 from working loose.

The present embodiment, as described above, employs a fan-cum-heat sink.Although a heat sink is usually provided for cooling the CPU 150, if theheat sink is a fan-cum-heat sink, the inventive radiator mechanism 100requires no more cooling fan, and the fan-cum-heat sink is configured togive versatility to the built-in cooling fan. This configuration wouldinhibit increased manufacturing costs, increased power consumption, andincreased noise caused by driving the cooling fans that would beentailed if a new cooling fan were provided.

Further, the present embodiment employs the fan-cum-heat sink 110 inwhich the cooling fan and the cooling fin are disposed in the same planeinstead of a fan-cum-heat sink in which the cooling fan is disposedabove the cooling fin. This structure may facilitate connecting thecooling fan 130 and the through hole of the motherboard 160. However, itis to be understood that the cooling fan 130 and the cooling fin 140need not be disposed in the same plane, as far as connection establishedbetween the cooling fan 130 and the through hole 166 of the motherboard130 is secured.

The cooling fan 130 used for the inventive radiator mechanism 100 is notnecessarily part of the fan-cum-heat sink. For example, a heat sink onlyincluding the cooling fin 140 may be provided as a cooling device forthe CPU 150, and the cooling fan 130 may be disposed in a positionunrelated to the cooling fin 140. For example, the cooling fan 130 maybe provided at a right-hand side (i.e., opposite the cooling fin 140) ofthe motherboard 160 in FIG. 1, or at the surface 164 of the motherboard160. The cooling fan 130 need not be necessarily mounted on themotherboard 160, but may be attached on the base 220 in the notebook PC200 that accommodates the motherboard 160, or on sheet metal for heatradiation or other members. In other words, as far as the cooling fan130 used for the inventive radiator mechanism 100 can introduce hot airat the both surfaces 162 and 164 of the motherboard 160 via the throughhole 166, and dissipate heat, it is optional whether the cooling fin 140is to be forcefully cooled or not. For example, only a provision ofventilation by the cooling fan 130 to eject hot air at the both surfaces162 and 164 of the motherboard 160 from a mesh of exhaust port (notshown) provided in the base 220 may suffice.

The motherboard 160 is a printed board mounted with circuit componentssuch as a CPU socket 151, a variety of memory (sockets), a chipset, anexpansion slot, and a BIOS ROM, and includes a front surface 162, a backsurface 164, and a through hole 166 that is pierced through the bothsurfaces 162 and 164. In FIGS. 1 and 2, a variety of other circuitcomponents to be mounted on the motherboard 160 are omitted.

Close to the CPU socket 151 are disposed a memory (SRAM, or the like),and a chipset for CPU. The chipset for CPU, which connects the CPU 150and the memory with each other, serves to control dataflow between theCPU 150 and the memory, and is typically disposed between the CPU 150and the memory. Both the memory and the chipset for CPU are exoergiccomponents. The through hole 166 is provided so as not to interfere withthe placement of the memory and the chipset for CPU.

The through hole 166 has a diameter of at least about 8 mm or larger,and preferably about 10 mm or larger, to provide ventilation with theback surface 164. The “about 8 mm” is intended to exclude a screw holeand inspection hole that are typically provided on the motherboard 160because this screw hole and the like are too small to provideventilation. Although the through hole 166 is provided in the shape of acircle in the present embodiment, applicable shapes are not limited tothis, but may include any shape such as an ellipse, and a polygon. Inother words, the through hole 166 has an area of at least about 16 πmm²or larger, and preferably about 25 πmm² or larger. The through hole 166need be connected to the cooling fan 130. The “connect” means that thecooling fan 130 is allowed to provide ventilation via the through hole166 with the back surface 164.

The through hole 166 may be one hole having the above area, but may alsobe separated into multiple holes having the total area enough to meetthe above area requirement when each area of the holes is summed up. Inthat event, the multiple holes are preferably provided in proximity toeach other. The proximity should be an extent enough to secureconnection between each hole and the cooling fan 130. For instance, thethrough hole 166 may be a mesh of holes provided on the motherboard 166.The shape and dimension of each hole may be the same as each other, ordifferent from each other.

An operation of the radiator mechanism 100 will be described herein, asan operation of the notebook PC 200 to which the radiator mechanism 100is applicable. A description will now be given of the operation of thenotebook PC 200, with reference to FIG. 5. FIG. 5 is a schematicperspective view of the notebook PC 200 according to the presentinvention. As shown in FIG. 5, the notebook PC 200 includes a liquidcrystal display (LCD) bezel frame 210 and the base 220 connected witheach other via a hinge 202. The LCD bezel frame 210 is provided with anLCD screen 212. Characteristically, the base 220 is made of plasticmaterial, having a thickness of about 50 mm or less, and preferably ofabout 20 through about 30 mm. The inventive radiator mechanism 100employs the fan-cum-heat sink 110, which does not dispose the coolingfan 130 above the cooling fin 140, but in the same plane, and thusmaintains a low-profile body of the base 220. The LCD bezel frame 210takes on substantially a rectangular shape so as to hold the LCD screen212.

The base 220 includes a keyboard section 222 for typing information in,and the keyboard may use any type and arrangement. Usable types of thekeyboard may include 101, 106, 109 and ergonomics, and usable keyarrangements include QWERTY, DVORAK, JIS, new-JIS, and NICOLA (NihongoNyuryoku Conthotium Layout).

The base 220 also includes a pointing device 224 that emulates part ofmouse functions. Despite the structure shown in FIG. 5, the pointingdevice 224 may include a mouse, a trackball, a trackpad, a tablet, adigitizer, a joystick, a joypad, a touch panel, and a stylus pen.

Moreover, the base 220 includes sheet metal for heat radiation and/orexhaust port (not shown) incorporated in a side portion 225. The sheetmetal for heat radiation and/or exhaust port is connected to the exhaustport 127. To be specific, the bottom surface 124 near the exhaust port127 may be connected with the sheet metal for heat radiation, and airemitted from the exhaust port 127 may be blown on the sheet metal forheat radiation, or emitted out from the exhaust port at the side portion225. The temperature of the fan-cum-heat sink 110, if connected with thesheet metal for heat radiation, constantly keeps an approximatelyspecific value (e.g., at room temperature).

In operation, a user of the notebook PC 200 operates the keyboard 222 orthe pointing device 224, and executes program stored in a hard disk (notshown) included in the base 220. In that event, the CPU 150 downloadsnecessary data from the hard disk and ROM (not shown) into memory (notshown). Heat produced from the CPU 150 at that moment is thermallytransferred via the thermally coupled housing 120 of the fan-cum-heatsink 110, and bottom surface 124 of the housing 124, to the cooling fin140. As a result, the heat is air-cooled by itself at a surface of thecooling fin 140 and the housing 120. Moreover, air blown from thecooling fan 130 forcefully cools the cooling fin 140.

Hot air derived from the memory, CPU chipset, other exoergic componentsmounted on the front surface 162 of the motherboard 160 is introducedfrom the intake 125 to the inside of the housing 120 by the cooling fan130 without passing through the through hole 166. The introduced hot airis exhausted from the storage portion (wind tunnel space) 128 to theexhaust port 127 by the cooling fan 130. The hot air is cooled by heatexchange with the cooling fin 140 and the housing 120 while passingthrough the storage portion 128. The cooling fin 140 is forcefullycooled by the cooling fan 130 as described above. Then, the airexhausted from the exhaust port 127 is blown to the sheet metal for heatradiation, and further cooled, or exhausted out from the exhaust portprovided at the side portion 225.

Hot air derived from the exoergic components mounted on the back surface164 of the motherboard 160 is introduced from the intake 125 via thethrough hole 166 to the inside of the housing 120 by the cooling fan130. The introduced hot air is exhausted from the storage portion (windtunnel space) 128 to the exhaust port 127 by the cooling fan 130. Thehot air is cooled by heat exchange with the cooling fin 140 and thehousing 120 while passing through the storage portion 128. The coolingfin 140 is forcefully cooled by the cooling fan 130 as described above.Then, the air exhausted from the exhaust port 127 is blown to the sheetmetal for heat radiation, and further cooled, or exhausted out from theexhaust port provided at the side portion 225.

Consequently, the CPU 150 and other circuit components are thermallyprotected, regardless of whether on the front surface 162 or the backsurface 164 of the motherboard 160. Accordingly, the circuit componentsin the notebook PC 200 does not suffer destruction, deterioration, ormalfunction due to heat, and thus a user may carry out an intendedprocess. Moreover, the base 220 made of a plastic material also does notresult in thermal deformation or low-temperature burn.

Although the fan-cum-heat sink 110 in the present embodiment, as hasbeen exemplarily described above, takes in air from both of the top andbottom surfaces of the motherboard 160, and exhausts the air from theexhaust port 127, the air may flow in the reverse direction. In thiscase, the exhaust port 127 is utilized as an intake, and thefan-cum-heat sink 110 exhausts the air from both of the top and bottomsurfaces of the motherboard 160. Such a configuration may also exhibitdissipation effects, and the claimed invention is not intended toexclude the configuration.

Although the preferred embodiments of the present invention have beendescribed above, the present invention is, needless to say, notrestricted to these embodiments, and it is to be understood that variousmodifications and changes may be made without departing from the spiritand scope thereof. For example, the electronic apparatuses to which theinventive radiator mechanism is applicable are not limited to thenotebook PCs, but may broadly include desktop PCs, word-processors,personal digital assistants (PDAs), or other portable electronicapparatuses (such as portable game machines, and various types ofdrives).

According to the inventive radiator mechanism and electronic apparatus,the lateral type cooling fan does not prevent the housing of electronicapparatus that accommodates the printed board from miniaturizing so muchas the longitudinal type cooling fan does. In addition, heat at the backsurface of the printed board may easily be dissipated as well with asingle cooling fan, thereby preventing destruction, deterioration, andmalfunction due to heat of the circuit components on the printed board.

What is claimed is:
 1. A radiator mechanism comprising: at least oneexoergic part; a board, including a front surface and a back surface, onwhich the exoergic part is to be mounted, said board including a throughhole; and a cooling fan that rotates around an axis perpendicular tosaid front surface of said board, absorbs air from both faces of saidcooling fan, and exhausts in a direction parallel to said front surfaceof said board; wherein said cooling fan dissipates heat from said frontsurface, and said through hole allows said cooling fan to dissipate heatthrough said through hole from the back surface of said board.
 2. Aradiator mechanism according to claim 1, further comprising a heat sink,wherein said cooling fan is provided in said heat sink.
 3. A radiatormechanism according to claim 2, wherein said heat sink includes aplurality of cooling fins, and said cooling fan and said cooling finsare disposed in the same plane.
 4. A radiator mechanism according toclaim 1, wherein said exoergic part is a processor, said board is amotherboard, and said cooling fan is provided at a side of the samesurface as a surface on which said processor is located.
 5. A radiatormechanism according to claim 1, further comprising a heat pipe, whereinsaid cooling fan cools heat conducted via said heat pipe.
 6. A radiatormechanism according to claim 2, further comprising a heat pipe, whereinsaid heat pipe and said heat sink are thermally connected.
 7. A radiatormechanism according to claim 1, wherein said cooling fan includes anintake connected to said through hole.
 8. The radiator mechanismaccording to claim 1, wherein the cooling fan comprises fan bladesoriented generally parallel to an axis of rotation of the cooling fan.9. The radiator mechanism according to claim 1, wherein the through holehas an area of at least about 16 πmm².
 10. The radiator mechanismaccording to claim 1, comprising a notebook computer, the notebookcomputer including a motherboard, and the through hole being through themotherboard.
 11. An electronic apparatus comprising: a board thatincludes first and second surfaces, and a through hole pierced throughsaid first and second surfaces; exoergic parts mounted on said first andsecond surfaces of said board; a cooling fan that rotates around an axisperpendicular to said first surface and dissipates heat from said firstsurface, while dissipating heat from said second surface via saidthrough hole; and a housing that accommodates said board and saidcooling fan; wherein said cooling fan absorbs inner air in said housingfrom both faces of said cooling fan and exhausts the inner air in adirection parallel to said first and second surfaces of said board. 12.An electronic apparatus according to claim 11, further comprising a heatsink, wherein said cooling fan is provided in said heat sink.
 13. Anelectronic apparatus according to claim 12, wherein said heat sinkincludes a plurality of cooling fins, and said cooling fan and saidcooling fins are disposed in the same plane.
 14. An electronic apparatusaccording to claim 11, wherein one of said exoergic part is a processor,said board is a motherboard, and said cooling fan is provided at a sideof the same surface as a surface on which said processor is located. 15.An electronic apparatus according to claim 11, further comprising a heatpipe, wherein said cooling fan cools heat conducted via said heat pipe.16. An electronic apparatus according to claim 11, wherein said coolingfan includes an intake connected to said through hole.
 17. Theelectronic apparatus according to claim 9, wherein the cooling fancomprises fan blades oriented generally parallel to the axis of rotationof the cooling fan.
 18. The electronic apparatus according to claim 11,wherein the through hole has an area of at least about 16 πmm².